Abstract:
The application provides in an aspect a process for producing urea in a urea plant comprising a high pressure synthesis section comprising a reactor, wherein the process comprises reacting NH 3 feed and CO 2 feed under urea formation conditions in said reactor to form a urea synthesis solution comprising urea, water, carbamate and ammonia, wherein the process further comprises contacting a carbamate- containing liquid stream with an equipment part of said high pressure synthesis section that is made of a ferritic steel alloy.
Abstract:
The invention pertains to a urea production process using a high pressure stripper and a low pressure decomposer connected to a low pressure carbamate condenser which is in heat exchanging contact through a wall with a sub - atmospheric decomposer wherein urea solution obtained from the low pressure decomposer is processed.
Abstract:
Disclosed is an integrated process for the production of urea and melamine, as well as a system for carrying out the process. The invention thereby pertains to an integrated process of the type wherein off-gas obtained from the production of melamine is entered into the process for the production of melamine, by condensation in the presence of water. A typical embodiment thereof is the condensation in the presence of an aqueous carbamate solution obtained from urea recovery. In accordance with the invention, said condensation takes place at a substantially lower pressure than the pressure at which the melamine off-gas is obtained. To this end, the pressure of the off-gas is reduced typically by 2-10 bar. In connection herewith, the system of the invention comprises a pressure reducing unit downstream of an outlet for the melamine off-gas, and upstream of a section for the condensation of the off-gas. The invention also includes a method for the modernization of an integrated system for the production of melamine and urea. This is accomplished by adding the aforementioned pressure reducing unit to a pre-existing system.
Abstract:
Disclosed is a method for the integrated production of two different urea products. One is an aqueous urea solution suitable for use in NOx abatement (generally indicated as Diesel Exhaust Fluid – DEF). The other is a solution used as a fertilizer, viz. Urea Ammonium Nitrate (UAN). The production of DEF and UAN are integrated as follows: ammonia recovered from the production of urea is used as a feed to the production of ammonium nitrate. At least part of an aqueous urea stream from urea production, is mixed with ammonium nitrate so as to obtain UAN.
Abstract:
In the present invention a method for treating algae is disclosed, which method comprises the steps of (a) providing an ionic liquid, which is a conjugate of an organic base with pK a at least 6 and an acid, (b) providing algae, (c) subjecting algae to cell lysis with the ionic liquid, whereby at least two phases are formed, including a hydrophobic phase and a hydrophilic phase, and (d) separating the hydrophobic phase containing lipids.
Abstract:
Disclosed is a process for the integrated production of urea and melamine. A urea production zone produces a urea synthesis stream comprising urea, water and ammonium carbamate. This stream is subjected to processing, preferably involving stripping, so as to separate an aqueous urea stream from residual dissociated carbamate vapor comprising ammonia, carbon dioxide, and water. The urea is fed to a melamine synthesis zone and subjected to melamine forming conditions so as to form melamine and off-gas comprising carbon dioxide and ammonia. The dissociated carbamate vapor and the melamine off- gas are subjected to combined condensation so as to form a dilute melamine off-gas condensate.
Abstract:
Disclosed is method for removing carbonyl sulphide and/or carbon disulphide from a sour gas stream. The method comprises subjecting the gas stream to simultaneous contact with an absorption liquid, such as an aqueous amine solution, and with a catalyst suitable for hydrolyzing carbonyl sulphide and/or carbon disulphide. To this end, the invention also provides a reactor system wherein both an absorption liquid and a catalyst are present. In a preferred embodiment, the catalyst is a heterogeneous catalyst present on or in an absorption column, either coated on the trays of a column with trays, or contained in the packing of a packed column.